In many clinical situations, before a proper diagnosis can be made and effective therapy instituted, it is necessary to identify a localized focus of disease deep within specific organs or tissues in the body; obtain a sample of tissue from the diseased region; and evaluate it histologically. Typical examples are the presence of a small mass in the breast of a woman or a nodule in the lung. In order to accurately diagnose and then effectively treat the disease, the breast mass or lung nodule, it often becomes necessary for a surgeon to excise a portion of the diseased tissue for microscopic examination and analysis. Thus, it is often necessary to insert long needles or wires, typically from four to eight inches in length, through the skin into the diseased region of the body, to include not only the breast or lung, but also deep seated organs such as the liver, kidney, and bony skeleton. Such needles are typically guided to their target tissue by any of a variety of imaging systems including X-ray fluoroscopy, computerized tomography, ultrasound, magnetic resonance and the like.
Generally, percutaneous insertion of objects such as needles, wires and catheters are employed to obtain biopsy specimens of the diseased tissues; drain abscesses; sample body fluids; and introduce medication or contrast agents into the body. The insertion of hollow needles, of various bore diameters and lengths, may also be the first step towards non-surgical placement of larger-bore catheters into the body of the subject by conventionally known means.
Precise positioning of the object to be surgically inserted, typically a small-bore needle, is simple in principle but is often difficult in practice. Initially, an appropriate and safe skin entry site is chosen; the site sterilized; and then infiltrated with a local anesthetic. The needle is then advanced into the tissues; its direction and depth checked repeatedly by one or more imaging systems; and adjustments made if necessary. The imaging system displays the internal target as well as the needle shaft and allows the surgeon to carefully aim the needle towards the target even though the target tissue may be small and deep seated. The ongoing and recurring problem, however, lies in the fact that it may be extremely difficult for the surgeon to maintain the needle at the exact angle required relative to the target tissue within the patient's body. In routine practice, the needle is inserted by hand and advanced part-way towards the estimated position of the target tissue site. The patient then is moved in and out of the viewing position of the particular imaging system to determine whether the needle is accurately aimed towards the target site; or whether the needle direction needs to be adjusted; and/or to determine how much further the needle should be advanced to reach the target tissue. This procedure may have to be repeated a number of times before completion.
The operator commonly improvises some support for the needle during this viewing period of time, often with a folded towel; or a stack of sterile swab pads; or some similar temporary arrangement, in order to maintain the needle in the inserted position until its relationship to the target tissue can be verified. This problem is compounded if the desired point of entry through the skin of the patient is on an oblique or vertical aspect of the body surface. It is often difficult to maintain the desired angle of entry in such instances and it is common for the surgeon to withdraw the needle and reinsert it at a different angle or aspect several times before the correct relationship to the target tissue is attained.
It is therefore commonly recognized that a device which would allow the surgeon to position a needle at the chosen skin entry site and to maintain the requisite angle of insertion into the tissue of the patient would be an extraordinarily useful and advantageous device. Such an article would not only allow for precise positioning of the needle to be inserted, but would also support the needle after initial insertion while its position within the body is being verified by the imaging system. It would also eliminate the requirement that the surgeon or surgical assistant physically grasp and maintain the inserted needle in position during the entirety of the verification procedure. Such a device would not only provide freedom, convenience and accuracy for the surgeon during the procedure, but also would provide greater comfort for the patient as well.